/*
* We need our own copy of the higher levels of the page tables
* because we want to avoid inserting EFI region mappings (EFI_VA_END
* to EFI_VA_START) into the standard kernel page tables. Everything
* else can be shared, see efi_sync_low_kernel_mappings().
*/
int __init efi_alloc_page_tables(void)
{
pgd_t *pgd;
pud_t *pud;
gfp_t gfp_mask;
if (efi_enabled(EFI_OLD_MEMMAP))
return 0;
gfp_mask = GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO;
efi_pgd = (pgd_t *)__get_free_page(gfp_mask);
if (!efi_pgd)
return -ENOMEM;
pgd = efi_pgd + pgd_index(EFI_VA_END);
pud = pud_alloc_one(NULL, 0);
if (!pud) {
free_page((unsigned long)efi_pgd);
return -ENOMEM;
}
pgd_populate(NULL, pgd, pud);
return 0;
}
static int __create_hyp_mappings(pgd_t *pgdp,
unsigned long start, unsigned long end,
unsigned long pfn, pgprot_t prot)
{
pgd_t *pgd;
pud_t *pud;
unsigned long addr, next;
int err = 0;
mutex_lock(&kvm_hyp_pgd_mutex);
addr = start & PAGE_MASK;
end = PAGE_ALIGN(end);
do {
pgd = pgdp + pgd_index(addr);
if (pgd_none(*pgd)) {
pud = pud_alloc_one(NULL, addr);
if (!pud) {
kvm_err("Cannot allocate Hyp pud\n");
err = -ENOMEM;
goto out;
}
pgd_populate(NULL, pgd, pud);
get_page(virt_to_page(pgd));
kvm_flush_dcache_to_poc(pgd, sizeof(*pgd));
}
next = pgd_addr_end(addr, end);
err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot);
if (err)
goto out;
pfn += (next - addr) >> PAGE_SHIFT;
} while (addr = next, addr != end);
out:
mutex_unlock(&kvm_hyp_pgd_mutex);
return err;
}
